JP2559515B2 - Fuel injection valve device and manufacturing method thereof - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection valve device for supplying atomized fuel to each cylinder of an internal combustion engine and a method for manufacturing the same.

[Conventional technology]

A conventional fuel injection valve device has, for example, two intake valves for one cylinder as disclosed in Japanese Utility Model Laid-Open No. 61-152765, and an intake passage has two or branched intake passage portions near intake. .

Such an injection valve has a fuel branch portion for dividing fuel injected from the injection hole downstream of a single injection hole for metering fuel, and a valve shaft center through which the fuel divided by the fuel branch portion flows. And two fuel passages that are inclined with respect to each other. The merging portion of the fuel passages on the fuel branch portion is formed upstream from the intersection of the fuel passage walls, and the shape of the intersection is always sharp. The edge is used to set the fuel injection angle and the fuel distribution to the left and right fuel passages to predetermined values.

[Problems to be Solved by the Invention]

Among the sprays from the injection holes, the above-mentioned conventional technology is not taken into consideration in that the sprays whose flow is restricted on the wall surface of the fuel branch portion are directly sprayed without coalescing and the particle size becomes large. However, there was a problem in that the fuel was atomized.

In addition, the above-mentioned branch portion has problems due to manufacturing, such as a slight positional deviation (angle change) and a change in shape due to processing, resulting in inferior fuel division accuracy and spray angle accuracy.

An object of the present invention is to provide a fuel injection valve device capable of promoting atomization and branching without changing the fuel injection amount from the injection hole.

Another object of the present invention is to provide a method for manufacturing a fuel injection valve device capable of promoting atomization and branching without changing the fuel injection amount from the injection hole.

[Means for solving the problem]

In order to achieve the above object, a fuel swirl element which is provided on the upstream side of the valve seat and applies swirl force to the supplied fuel,
A fuel injection valve device comprising a fuel injection hole provided on the downstream side of the valve seat and a flow dividing means for dividing the flow of fuel sprayed on the downstream side of the fuel injection hole, wherein the flow dividing means is provided. A central fuel passage hole is provided in which the width of the fuel passage hole on the outlet side is smaller than the width of the fuel passage hole on the inlet side, and the fuel passage hole is formed to spread radially from the fuel passage hole.

In order to achieve the above-mentioned other object, a fuel swirl element provided on the upstream side of a valve seat for giving swirling force to the supplied fuel, a fuel injection hole provided on the downstream side of the valve seat, and the fuel A fuel injection valve device, comprising: a flow dividing means for dividing the flow of fuel sprayed on the downstream side of the injection hole, by locally pressing the periphery of the outlet side injection hole of the axial fuel passage, It is manufactured by narrowing down the inner diameter of the ejection hole.

[Action]

The fuel flow dividing means provided in the lower part of the single injection hole always injects a constant spray amount from the injection hole, and smoothly branches and distributes to the two large-diameter fuel passage sides adjacent to the axial fuel passage. .

As a result, the dripping of the sprayed fuel at the branch point is eliminated, and stable spraying is performed.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 10.

FIG. 2 is a longitudinal sectional view of the electromagnetic fuel injection valve 1 according to the present invention. The injection valve 1 is for injecting and supplying fuel by opening and closing a seat portion in accordance with a duty ON-OFF signal calculated by a control unit (not shown). The electric signal is applied to the electromagnetic coil 2 as a pulse. When a pulsed current flows through the coil 2, a magnetic circuit is formed by the magnetic core 3 at the center, the yoke 4 serving as an outer cylinder, and the plunger 5 axially opposed to the core 3, and the plunger 5 is on the core 3 side. Is sucked into. When the plunger 5 moves, the ball valve 6 integrated with it moves away from the seat surface (valve seat) 9 of the valve guide 7 and opens the fuel injection hole 8 (hereinafter referred to as “orifice”). The ball 6 includes a rod 10 which is integrated with one end of a plunger 5 made of a magnetic material, a ball 11 which is welded or integrally formed to the other end of the rod 10 and a non-magnetic material which is fixed to the upper opening of the plunger 5. The guide ring 12 and the guide ring 12 are each guided by the inner peripheral surface of the cylindrical fuel swirl element 13 inserted and fixed in the inner wall of the hollow portion of the valve guide 7 during movement. Also, the stroke amount when moving is determined by the receiving surface 10 of the flange portion of the rod 10.
It is determined by the size of the gap between a and the stopper 14.

On the other hand, the valve guide 7 is formed with a cylindrical portion 15 extending in the direction opposite to the seat surface 9, and an adapter 16 which is a fuel flow dividing means according to the present invention is inserted and fixed therein.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2, and shows the fuel swirl element 13 for supplying swirl fuel to the orifice 8. The fuel swirl element 13 is provided with an axial groove 13a and a radial groove 13b, and the axial groove 13a is formed by partially cutting the outer peripheral surface of a cylindrical material. Moreover, the groove concerned
13a and 13b are fuel passages introduced in the axial direction, but the groove 1
The fuel passing through 3a is introduced eccentrically around the shaft center in the groove 13b. The so-called fuel is given a turning force and supplied to the orifice 8 of the valve guide 7. The turning force is adjusted by the amount of eccentricity L.

FIG. 6 is a view taken in the direction of arrow P in FIG. 2 and shows the adapter 16 which is a fuel flow dividing means. The adapter 16 has a fuel passage hole 16a having a width slightly larger than the axial center orifice 8 on the inlet side, a fuel passage hole 16b having a width slightly smaller than the axial center orifice 8 on the outlet side, and parallel to the passage hole 16a. It has two large-diameter fuel passage holes 17 arranged at intervals, and each of the fuel passage holes 17 extends radially through the passage holes 16a and 16b of the axial center to communicate with each other in an infinity shape to form a fuel passage. Is forming.

4 and 5 show the injection mechanism from the inflow of fuel, and diffusion along the two fuel passages 17 side (θ ₁ )
However, the fuel is narrowed down in the direct direction with respect to the line connecting the two fuel passages, and the fuel ejection angle (θ ₂ ) is equal to the ejection angle (θ ₂ ).
₁ ) It is shown to be smaller than. That is, in FIG. 4, the fuel 19 flowing in from above passes through the fuel swirl element 13, is measured by the ball 11 and the seat surface 9 of the valve guide 7, is swirled, and moves to the orifice 8. The width D of the fuel passage hole 16a at the axial center of the fuel sprayed from the injection hole 8 is
Since the width is slightly larger than the width d of the passage hole 16b on the outlet side, the spray amount does not change.

Further, the fuel that is ejected and spread spreads against the side wall of the passage hole 16a, but since the inner peripheral walls of the two adjacent large passage holes 17 are continuously connected with a smooth curvature radius, the two fuel are transmitted through the wall. It is introduced into the passage hole 17 and distributed in two directions,
It spreads to the left and right at the exit and is sprayed. Here, the relationship between the inner diameter D ₀ of the orifice 8 and the inlet width D of the fuel passage hole 16a is D ₀ <
D, and the relationship between D and the outlet width d of the fuel passage hole 16a is D
By setting> d, it is possible to eliminate the change in the spray flow rate due to the flow resistance in the fuel injection holes 8 and to reliably distribute the distribution of injection in two directions.

That is, when D <D ₀ , the fuel once measured from D ₀ is further throttled by D, and the injection amount changes.

However, when D becomes considerably larger than D ₀ , the swirling force of the fuel is weakened and the spray angle and particle size at the time of two-way separation are adversely affected, so D = 1.1 D ₀ is preferable.

In the above-mentioned embodiment, by reducing the fuel ejected to the central portion of the shaft center, the fuel adhering to a place other than the intake valve of the engine is reduced, so that the required amount from the engine control unit can be surely satisfied and the atomized fuel Can be effectively sent to the engine.

That is, the fact that the fuel injection amount in the axial center portion can be reduced means that when the engine is used by being attached to a double intake engine, almost no fuel collides with the partition wall of the intake valve portion and the air and the fuel are mixed well. Therefore, there is no delay in the transient characteristics of the engine, and the response of the engine can be improved.

Further, since it is possible to achieve atomization of fuel equivalent to that of the conventional upstream swirl type injector, it becomes an effective means for countermeasures against exhaust gas such as hydrocarbon.

The size of the outlet diameter of the fuel passage hole 16a of the adapter 16 can be selected depending on the spray angles θ ₁ and θ ₂ and the desired distribution condition, and can be arbitrarily set as necessary.

FIGS. 7A to 7c show another embodiment, which is a range (D = 1.1D _{0 to} 1.5) in which the spray amount is not largely changed between the inlet width D and the outlet width d of the fuel passage hole 16a. The range of D ₀ is preferable), and the structure in which D at the inlet is secured and the taper is made from the middle portion and the outlet d is straightened, or the inlet width D
It is conceivable that the structure has a taper shape from the end to the outlet width d (Fig. 7c). In any case, the structure must not interfere with the flow path of the fuel sprayed from the orifice 8.

In the embodiment described above, when observing the fuel injection state in FIG. 8, when the fuel passage hole inlet width D is made equal to the outlet width d, the distribution injection amount is relatively 4 (cc / min). It was confirmed that the amount of injection at the axis was large, but the distribution was not necessarily good. On the other hand, when the width d of the outlet of the fuel passage hole is narrowed to d = 1 / 5D as in the embodiment of the present invention, the fuel distribution is very good, the injection amount at the axial center is extremely small, and the fuel drop is effectively improved. Was confirmed.

Next, a method for processing the fuel passage hole of the adapter 16 will be described with reference to FIG.
It will be described with reference to FIG.

In the figure, an upper die set 102 that moves up and down is set on a lower die 100 via a tie rod pin 101. Then, the backing plate 103 is fixed to the lower die 100, and the guide plate 104 is placed thereon.

On the other hand, below the upper die set 102, a sub guide pin 106 for determining a punch stroke and a punch 107 are fixed via a punch plate 108.

In addition, 108 is a product pressing pin via the guide pin 109, the punch plate 108, the punch 107 and the sub guide pin 106.
It is set between the slippers 110 for guiding the.

In the above apparatus, first, the adapter 161 made of an intermediate material in which the fuel passage holes 16a and 17 are formed is placed on the packing plate 103. Since this adapter is usually placed in the gas of the engine, a stainless steel type is used. And punch 10
When 7 is lowered until the stopper (which normally controls the upper die set) works, a pair of circular punches 107
Presses the end face near the center of the fuel passage hole. As a result, as shown in Fig. 10, an indentation 105 of several mm is left on the end face, and only the material in the vicinity is plastically deformed toward the center, and it is narrowed down to about 1 / 5D width. Use as a passage hole.

FIG. 12 shows a method of molding the adapter 16 as described above,
Adapter of intermediate material to prevent deformation of fuel passage hole
When the mandrel pin 111 is placed on the 161, the shape of the mandrel pin 111 is prevented from being deformed during plastic deformation.

According to this forming method, the exit of the fuel passage hole can be easily and accurately processed by a punch press, and since the repeatability is high, uniform products can be mass-produced.

Further, in the case where the fuel passage hole is formed by using the mandrel pin, the product accuracy is further enhanced and a highly reliable product can be obtained.

〔The invention's effect〕

According to the present invention, atomization can be promoted and branched without changing the injection amount from the fuel injection hole, so that a fuel injection valve device with high ignitability can be provided.

Further, since the outlet side of the fuel injection hole is processed by the plastic change by the punch press, it is possible to provide a manufacturing method suitable for productivity as well as uniform quality.

[Brief description of drawings]

The drawings show a fuel injection valve device and a manufacturing method thereof according to the present invention, and FIG. 1 is a schematic view of a flow dividing means showing a fuel injection state,
FIG. 2 is a sub-sectional view of the electromagnetic fuel injection device, and FIG.
III-III sectional view of FIG. 4, FIGS. 4 and 5 are enlarged sectional views of the main part of FIG. 2, FIG. 6 is a view taken in the direction of arrow P of FIG. 2, FIG. 7A is a top view of the adapter, and FIG. 7B. 7A is a sectional view taken along line VII-VII in FIG. 7A, FIG. 7C is a sectional view taken along line VII-VII in FIG. 7A in another embodiment, FIG. 8 is a fuel injection characteristic diagram, FIG. 9 is a sectional view of an adapter manufacturing apparatus,
FIG. 10 is a semi-longitudinal sectional view of the adapter, FIG. 11 is a bottom view of the adapter, and FIG. 12 is a sectional view of another adapter manufacturing apparatus. 16 …… Adapter, 16a …… Fuel passage inlet, 166 …… Fuel passage outlet, 107a …… Punch.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Yoshio Okamoto 502 Jinrachicho, Tsuchiura City, Ibaraki Prefecture Machinery Research Laboratory, Hitachi, Ltd. Inside the Sawa Plant (72) Inventor Atsushi Koshizaka, Takada, Katsuta, Ibaraki, Takaba, 2477 Kashima Yatsu, Hitachi Automobile Engineering Co., Ltd. (72) Inventor, Hironori Shinozaki Katsuta, Ibaraki, Ibaraki Kashima Yatsu 2477 Address 3 Hitachi Automobile Engineering Co., Ltd. (56) References JP-A-1-301955 (JP, A) JP-A-3-164564 (JP, A) SAI 61-152765 ( JP, U) Actual Kaihei 3-102059 (JP, U)

Claims (7)

(57) [Claims] 1. A fuel swirl element which is provided on the upstream side of a valve seat and gives a swirling force to the supplied fuel, a fuel injection hole which is provided on the downstream side of the valve seat, and a downstream side of the injection hole. Position to,
A fuel injection valve device comprising a flow dividing means for dividing the flow of fuel to be sprayed, wherein the flow dividing means is a central fuel passage in which a fuel passage hole width on the outlet side is smaller than a fuel passage hole width on the inlet side. A fuel injection valve device comprising a hole, and a fuel passage hole radially extending from the fuel passage hole. 2. The fuel injection valve device according to claim 1, wherein the outlet side of the central fuel passage hole is constituted by a part of the flow dividing means. 3. The fuel injection valve device according to claim 1, wherein the flow dividing means is made of a metallic adapter and has a fuel passage hole that gradually narrows toward the downstream side. 4. A fuel swirl element provided upstream of the valve seat for giving swirl force to the supplied fuel, a fuel injection hole provided downstream of the valve seat, and a downstream side of the injection hole. Position to,
A fuel injection valve device comprising a flow dividing means for dividing a flow of fuel to be sprayed, wherein the flow dividing means is formed by an adapter concentrically arranged and fixed to a valve guide, and formed at the center of the adapter. A through hole having an inlet width larger than the injection hole of the valve guide and an outlet width smaller than the injection hole; and at least a pair of ∞-shaped through holes extending radially including the through hole. Characteristic fuel injection valve device. 5. The fuel injection valve device according to claim 4, wherein the outlet through hole is formed by deforming the adapter around the central through hole. 6. A fuel swirl element provided upstream of the valve seat for giving swirling force to the supplied fuel, a fuel injection hole provided downstream of the valve seat, and downstream of the injection hole. Position to,
A fuel injection valve device comprising a flow dividing means for dividing the flow of fuel to be sprayed, wherein the periphery of the outlet fuel passage hole in the central portion is locally axially pressed to narrow the width of the passage hole. A method of manufacturing a fuel injection valve device characterized by the above. 7. A method of manufacturing a fuel injection valve device according to claim 6, wherein the periphery of said outlet side fuel passage hole is pressed and narrowed by a pair of punches.